[0001] The present invention relates to a method shown for instance in
US 2011/0181045 A1 for controlling a torque performance of an electrical pitch motor in a system comprising
an electrical pitch-control system said pitch motor controls a turbine blade, said
pitch-control system comprises
- a first unit comparing a received reference pitch-angle Pr with an actual pitch-angle
Pa of the turbine blade, said Pa-value is registered by and received from a resolver,
and that the first unit further regulates the pitch-angle of the turbine blade according
to the received pitch-angle values,
- after the first unit an electrically connected second unit said second unit compares
a reference-speed Sr received from the first unit with an actual speed Sa of the rotational
speed of the motor, said resolver measures and calculates the actual speed Sa which
is send to the second unit and that the second unit regulates the rotational speed
of the motor according to the received speed values
- after the second unit an electrically connected third unit comparing a reference torque
Tr of the motor - said value is received from the second unit-with the actual torque
Ta of the motor, said third unit further regulates the torque performance of the motor
according to the received torque-references;
- said control system further comprises a first overload unit between the third unit
and the motor.
[0002] The invention also relates to an electrical pitch-control system adapted to control
a torque performance of an electrical pitch motor said pitch-control system comprises
- a first unit comprising a first summator adapted to compare a received reference pitch-angle
Pr with an actual pitch-angle Pa of a turbine blade, said Pa-value is provided by
a resolver, and that the first unit further comprises a first control unit adapted
to regulate the pitch-angle of the turbine blade
- after the first unit an electrically connected second unit comprising a second summator
adapted to compare a reference-speed Sr received from the first unit with an actual
speed Sa of the rotational speed of the motor, measured by the resolver
- and a second a second control unit adapted to regulate the rotational speed of the
motor and after the second unit an electrically connected third unit comprising a
third summator adapted to compare the reference torque Tr of the motor - said value
is received from the second unit - with the actual torque Ta of the motor, and that
the third unit further comprises a third control unit adapted to regulate the torque
of the motor
- said control system further comprises a first overload unit between the third unit
and the motor.
[0003] The invention further relates to use of the electrical pitch-control system according
to the invention for carrying out the method according to the invention.
[0004] Finally, the invention relates to use of the method according to the invention and
according to the electrical pitch-control system for regulating a turbine blade of
a wind turbine.
[0005] The electrical pitch system is operating the turbine blades of a wind turbine, WT.
This is also called "pitch operation". An electrical motor is the actuator moving
each individual blade. A typical WT has three turbine blades, whereas the numbers
of individually operated motors are three. The electrical pitch system is also forming
the interface to the electrical system of the nacelle, wherefrom it receives a set
points for the pitch and the electrical power to operate the motors and thereby the
blades.
[0006] There are two main features for the pitch system; one is the normal operation, where
the pitch is used to optimize the lift of the turbine blade in all wind situations.
The other is the very important main brake of the wind turbine. This brake function
operates by moving the turbine blade from the operation position (from 0° to 30° depending
on the actual average wind speed) to the vane position. This is 90°.
[0007] As the pitch system is the only brake for the wind turbine the three motors have
to be controlled individually and independent from each other.
[0008] Thus, it is important that the rotor blades of the wind turbine can be pitched and
adjusted properly.
[0009] If a wind turbine must be stopped each rotor blade is pitched in such a way that
the leading edge of the wing is turned towards the wind whereby a braking of the wings
of the wind turbine takes place. The adjustment of each wing takes place independently
of the other wings.
[0010] The pitch-control systems are generally used to pitch/adjust the wings in relation
to the wind or the water flow in such a way that the wings adapt the right angel in
relation to the wind load alternative the water flow load.
[0011] During the production of power to the grid, there are two operations situations:
- 1) Production of power below nominal level: In this mode, the average wind speed is
below a level, where the Wind Turbine rotor is able to harvest wind enough to produce
nominal power. Therefor the pitch angle is set to the optimal values as a function
of the average wind speed. For a standard wind turbine, the level will be +/- 2º with
respect to 0° pitch angle. The pitch speed will be very low, typically below 0,5 °/s.
- 2) Production of power at nominal level: In this mode, the wind turbine rotor can
harvest enough energy so that the Wind Turbine can produce nominal electrical energy,
which is delivered to the grid. In this operation mode, the energy of the wind has
to be limited by pitching the blades to a position, where the blade airfoil is less
optimal. In this operating mode, the pitch angle is between 2 to 30°. The pitch speeds
are typical higher at low absolute pitch angles and lower at higher absolute pitch
angles. The pitch speed can be up to 10 °/s, depending on the size of the WT, the
gusts and the turbulence of the wind.
[0012] The turbulence is according to the guidelines for wind turbines calculated to 20%
of the average wind speed.
[0013] When the nominal power has been reached, the pitch angel is corrected in order to
limit the torque on the motor spindle.
[0014] Gusts are a critical factor for the rotor blades and for the pitch-control system
as the rotor blades typically must be pitched/angled very fast when the rotor blades
are moved into gusts.
[0015] A gust can have either positive or negative wind speed in relation to the average
wind speed. Typically, a blade is passing through a gust within max. one second. When
the next blade arrives to the gust area, the gust can be almost vanished and the gust
influence of this rotor blade may be nearly zero.
[0016] The peak values obtained during a gust can reach a level of 100 to 300% of the nominal
torque of the motor shaft. Thus, the pitch motor must withstand a torque that might
be three times the necessary torque during normal operation in order to withstand
those huge torque impacts, which typically take place 9-10 times per year.
[0017] Thus in the system known from prior art it is necessary to oversize the motor with
a factor of 3 and thereby oversize the gear system and the frequency converter in
order to meet the rare torque impacts which try to press the turbine blades out of
the wind. It causes that the costs of production of the wind turbine are increased
considerable.
[0018] The oversized motor- and gear-systems are used only for about 1% of the lifetime
of a wind turbine and is therefore an expensive unit compared to the utilization factor.
By an overload of e.g. 20% an integrator starts summing. If the level is getting to
high, the torque is turned down to avoid a thermal overload situation.
[0019] In case the limit is set to 20% the integrator will be summing the difference between
Tnom and Tact multiplied by 1,2, where Tnom is the nominal torque and Tact is the
actual torque.
[0020] The maximum torque value that comes out of the integrator is Tmax, thus being the
limiting torque level.
[0021] If Tact is greater than the limiting torque level, the torque value will change in
such a way that the torque performance of the motor may be limited further. That is,
the motor cannot provide the torque the situation actually requires. Therefor it is
necessary with a very large motor in order to prevent the situation arises. As mentioned,
the motor must be enlarged with a factor 3 to cope with the torque demand, which takes
place in 1% of the cases (compared with the situation in 99% of the cases).
[0022] DE102010035055 discloses a method for controlling a pitch angel of a rotor blade. A pitch motor
adjust the pitch angel comparing an actual pitch angel with a target-value for the
pitch angel of the rotor blade. A target-value for the torque of the pitch motor is
calculated and the pitch angel of the rotor blade is adjusted as a function of the
actual rotational speed of the pitch motor, the calculated target-value for the torque
and finally the target-value for the pitch angel of the rotor blade. By this technology,
a more precise position of the pitch adjustment should be obtained.
[0023] However, it is desirable that the adjustment may be carried out faster than is the
case for this system mentioned above and in such a way that an overload of the pitch
motor is avoided. Further, it is desirable that it is possible to reduce the dimension
of the pitch motor because of the load being reduced. Therefore, it is desirable to
limit the torque and thus reduce the dimension of the pitch-control system thus being
able to select a smaller motor and in addition a smaller frequency converter.
[0024] It is an object of the present invention to provide a system which does not have
the above disadvantages of the prior art or which at least provides a useful alternative
to the prior art.
[0025] This is achieved with a method as mentioned in the introduction, and where
- the control system further comprises a second overload-unit said second overload unit
receives an error- speed- signal Se which is the difference between Sr and Sa registered
by the second unit
- said second overload unit compares Se with a maximal allowable speed value Smax, and
that the second overload unit sends a signal to the motor for the regulating of the
torque performance of the motor said signal is a function of the value of Se.
[0026] This is also achieved by a electrical pitch-control system a as mentioned in the
introduction and where
- the control system further comprises a second overload-unit said second overload unit
is adapted to receive an error-speed-signal Se which is the difference between Sr
and Sa registered by the second unit, said second overload unit is adapted to compare
Se with a maximal allowable speed value Smax,
- and that the second overload unit is adapted to send a signal to the motor at which
signal the torque performance of the motor is regulated, said signal is a function
of the value of Se.
[0027] Thereby the rotational speed of the motor is used as an additional parameter to control
the motor output/performance torque of the pitch motor. This parameter in conjunction
with the incorporating of the second overload unit results in that a gust of wind
is detected and handled much earlier compared with prior art. This will allow the
motor's torque performance to be activated earlier so that the motor torque is utilized
better.
[0028] Hereby the size of the motor can be reduced. By the reduced motor size, the rotor
blade controlled by the motor in question is pitched out but in a very short time
interval, which does not have a significant impact on the operation of the wind turbine.
[0029] The actual pitch position of the rotor blade may thus be moved away from a reference
value and without the position results in an error mode. The control units sees to
eliminate differences between the reference values and the actual values. If the reference
values are changed the actual values are also changed in such a way that no difference
occurs between the values. However, a difference between the actual position Pa for
a turbine blade and the reference position Pr for the turbine blade does not cause
an error message.
[0030] That is the rotor blade may follow the aerodynamic influence when a gust hits the
rotor blade. The torque of the motor needs not to be so large that it is able to withstand
the force on the turbine blade. This is in contrast to the todays known technology
where a difference is not accepted between Pr and Pa.
[0031] Thus, the invention includes that a speed error is included as an additional parameter
for regulating the torque of the motor.
[0032] The error-speed-signal Se is incorporated as an extra parameter as Se is the difference
between the reference speed and the actual speed of the rotation of the motor: Sref-Sact.
This value is taken from the summator of the second units and is treated in the second
overload unit. A maximal allowable speed value Smax is defined in advance and the
value is typically around 50-100rpm. Preferably at 100rpm.
[0033] The invention also results in that a gust is registered at an earlier stage and the
size of the pitch motor may be reduced. Further the reduced motor torque will cause
that the rotor blade is leveled out that is the actual pitch angel compared to the
reference angel is permitted to be different without causing an error message, which
will trigger an action that will result in the wind turbine stops producing power.
It is noted that the resolver is connected between the motor and the first unit.
[0034] In a further advantageous embodiment according to claim 2 is the signal a maximum
and preset torque value Tmax when Se is greater than Smax, and the signal to the motor
is the torque value Ta received from the third unit when Se is less than or equal
to Smax.
[0035] As a result of the extra overload unit is incorporated the level for counteracting
a peak-torque is now reduced. From having to counteract a torque that is 3 times the
nominal torque, it suffices to counteract 1.5-2 times the rated torque. 5
[0036] The torque performance value - the signal - to the motor is either Tmax - which is
a constant and pre-defined value - or Ta.
[0037] The value for the torque Tmax is a function of the nominal torque value for the motor
and Tmax is set to 1,5-2 times the nominal torque value preferably 1,5.
[0038] In a further advantageous embodiment according to claim 3, the first unit comprises
a first summator for comparison of the reference pitch-angle Pr with the actual pitch-angel
Pa of the turbine blade, and that the first unit further comprises a first control
unit for regulating the pitch-angle of the turbine blade
- and that the second unit comprises a second summator for comparison of the reference
speed Sr with the actual speed Sa and comprises a second control unit for regulating
the rotational speed of the motor
and that the third unit comprises a third summator for comparison of the reference
torque Tr of the motor with the actual torque Ta of the motor and that the third unit
further comprises a third control unit for regulating the torque of the motor.
[0039] This is an appropriate way to design the circuit in order to provide the process.
[0040] In a further advantageous embodiment according to claim 4 the second overload unit
comprises a comparator and a switch said comparator receives the speed signal Se from
the second unit, said comparator compares Se with the maximum value for the speed
Smax
- and that the comparator sends a signal to the switch that forwards the signal in such
a way, that a signal to the motor for adjustment of its torque is a maximum and predetermined
torque value Tmax when Se is greater than Smax
- and that the signal to the motor is the torque value Ta, which is a torque value received
from the third unit when Se is less than or equal to Smax . The comparator receives
the error-speed-error signal Se from a summator belonging to the second unit.
[0041] The switch takes two different positions an upper position where the Ta value is
used and a lower position where the Tmax value is used.
[0042] In a further advantageous embodiment according to claim 5 the switch comprises a
selector by which a comparison of the incoming speed value of Se is evaluated in relation
to Smax and in such a way that the value "fault" is chosen when Se is less than Smax
and the value "true" is chosen when Se is greater than Smax.
[0043] The actual pitch-angel Pa of the rotor blade is different from the reference pitch-angel
Pr when the torque performance is the Tmax value whereby the rotor blade is following
the aerodynamic influence of a wind.
[0044] The control system is adapted to accept the value. That is by strong gusts where
the motor provides a Tmax value the pitch angel may be different from the reference
value, which is considered optimal and without any error of the system is triggered.
The second overload unity causes that the torque of the motor is activated earlier
than is the case for the known technology. This ensures that the peak-torque is present
in a much shorter period of time than is the case if the second overload unity was
not present. By this arrangement is it allowed that the rotor blade is levelled off
and without causing damage to the system and/or causing an error.
[0045] The control system is connected to a main control system taking care of the overall
management of the electrical components forming part of the control and of the regulation
of a wind turbine.
[0046] The invention will be explained with reference to the drawing where
Fig 1 shows a pitch-control system according to the invention comprising a first and
a second overload unit.
Fig. 2 shows a detailed drawing of the second overload unit outlined in fig. 1.
Fig. 3 shows the effect of the wind speed on the pitch angel and on the torque output
of the pitch motor as a function of the time.
[0047] Fig 1 shows a pitch-control system according to the invention comprising a first
13 and a second 14 overload unit.
[0048] The pitch-control system 2 controls the torque performance of an electrical pitch
motor 1. The motor 1 controls a rotor blade - not shown at the figure. The control
system 2 comprises a first unit 3 comprising a first summator 4 for comparing a reference
pitch angel Pr with an actual pitch angel Pa of the rotor blade. A resolver 5 registers
the Pa-value and is switched in between the motor 1 and the first unit 3. An integrator
17 is switched in between the summator 4 and the resolver 5. The first unit 3 also
comprises a first control unit 6 for regulating the pitch angel of the rotor blade.
[0049] The first unit 3 is electrical connected to a second unit 7. An integrator 17 is
switched in between the two units. The second unit 7 comprises a second summator 8
comparing a reference speed Sr for the rotational speed of the motor 1, and received
from the first unit 3, with an actual speed Sa for the rotational speed of the motor
1. The resolver 5 registers the speed Sa and sends the value to the second unit 7.
The second unit 7 also comprises a second control unit 9 regulating the rotational
speed of the motor 1.
[0050] The second unit 7 is electrical connected to a third unit 10. An integrator 17 is
switched in between the two units. The third unit 10 comprises a third summator 11
comparing a reference torque Tr of the motor 1 - received from the second unit 7 -with
the actual torque Ta of the motor 1. Further, the third unit 10 comprises a third
control unit 12 that contributes to regulate the torque of the motor 1.
[0051] The control system 2 also comprises a first overload unit 13 between the third unit
12 and the motor 1 and further a second overload unit 14. The first overload unit
13 works by well-known principles. The second overload unit 14 receives an error-speed-signal
Se - which is the difference between the Sr and the Sa - from the summator 8 of the
second unit 7. The second overload unit 14 compares Se with a maximum permissible
value for the speed: Smax and the second overload unit 14 sends a signal to the motor
1 for setting the torque of the motor 1. Smax is set to a fixed value preferably 100rpm.
[0052] When Se is greater than Smax the signal to the motor 1 is a maximum and predefined
torque value Tmax. Is Se less than Smax the signal to the motor 1 is an actual torque
value Ta, which is the torque value, received from the third unit 10.
[0053] The value of the torque Tmax is a function of the nominal torque value of the motor
and 1,5-2 times greater than the nominal torque value. 1,5 is preferably chosen. Thereby
the level for counteracting a peak level is reduced in such a way that it just corresponds
to 1,5-2 times the nominal torque instead as is the case for prior art technology
3 times the nominal torque level.
[0054] The second overload unit 14 comprises a comparator 15 and a switch 16, see fig 2,
in which the mode of action is described in more detail. The comparator 15 receives
the speed signal Se - which is the difference between Sr and Sa - from the summator
8 of the second unit 7. The comparator 15 compares Se with the maximum value for the
speed Smax and the comparator sends a signal to the switch 16. The switch 16 receives
the signal from a first unit 25, in which the third unit 10 sends the signal: the
constant Tmax, or from a connection 26, that delivers the value Ta. The switch 16
forwards the signal in such a way that the torque-setting signal to the motor 1 is
Tmax when Se is greater than Smax. The signal to the motor 1 is the torque value Ta,
which is the torque value, received from the third unit 10 when Se is less than Smax.
Thus, the switch 16 takes up two positions: an upper position where the Ta value is
used and a lower position where the Tmax value is used. A selector built into the
switch 16 chooses the value "false" when Se is less than Smax and chooses the value
"truth" when Se is larger than Smax.
[0055] Fig. 3 shows the effect of the wind speed on the pitch angel and on the torque performance
of the pitch motor as a function of the time and using the invention.
[0056] The connection of the second overload unit 14 is shown during normal operation and
during overload, which takes place during a mighty gust. An important function of
the second overload unit 14 is that the actual pitch position Pa is admitted to move
away from the reference value for position Pr and without the position outcome is
resulting in an error message.
[0057] The upper figure 3 demonstrates the gust-situation. The time [sec] is specified out
of the X-axis and the wind [m/sec] is specified out of the Y-axis. The gust starts
at the vertical line leftmost.
[0058] The middle figure 3 shows the actual pitch angel Pa shown with reference number 18
and the reference pitch angel Ps is shown with the reference number 19. Pa may deviate
from Pr without causing an error mode. The time [sec] is specified out of the X-axis
and the pitch angel [º/s] is specified out of the Y-axis.
[0059] The bottom figure 3 shows the activating of the second overload unit 14 and the torque
limitation at the line with reference number 20. The torque [Nm] is specified out
of the Y-axis, and the time [sec] is specified out of the X-axis. The line with the
reference number 21 shows the torque as it would be if the second overload unit 14
were not activated.
[0060] The vertical line at the top left shows the beginning of a gust of wind. The upper
horizontal line 22 is the nominal torque multiplied by 1,5, the lower horizontal line
23 is the maximum nominal torque Tmax, while the middle horizontal line 24 is the
nominal torque multiplied by 1,2.
[0061] The torque output of the motor 1 at the point A shows the situation where the torque
output reaches the value 20% above the nominal torque, and the point B shows that
the performance reaches the level: the nominal torque multiplied by 1,5; this is the
point the second overload unit is activated. At the point C the value for Se is below
Smax and the second overload unit is deactivated whereby the torque curve drops.
[0062] Thus, it is possible to activate the torque T earlier in the gust activity. Because
the second overload unit is activated the maximum torque is present in a much shorter
period of time than is the case in prior art.
[0063] The difference in the area limited by the line with ref. 20 relative to the area
limited by the line with ref. 21 shows the difference in the applied torque and, therefore,
that the overall torque performance/output, during the time the gust is present, is
less when the second overload device 14 is incorporated. The torque - which is required
when using the invention - is therefore considerably less. It is possible with the
invention to enable torque output from the engine at an earlier point in the gust
activity.
[0064] An example: The maximum acceleration is typically 8 to 10 ° / s for a pitch-control
system. Since the available torque is 150% - compared with 300 % as it is known from
prior art - the pitch angling is more slowly and a speed of 4-5 ° / s can be expected.
As the wind gusts typically are less than one second, the pitch error will be less
than 4 to 5 ° according to this invention. This is also an advantage for the gearbox
and the gear wheels when the level of the torque is limited from 300% to 150% compared
with the prior art systems. Thus, these components can be reduced in dimensions.
1. Method for controlling a torque performance of an electrical pitch motor (1) in a
system comprising an electrical pitch-control system (2) said pitch motor (1) controls
a turbine blade, said pitch-control system (2) comprises
- a first unit (3) comparing a received reference pitch-angle Pr with an actual pitch-angle
Pa of the turbine blade, said Pa-value is registered by and received from a resolver
(5), and that the first unit (3) further regulates the pitch-angle of the turbine
blade according to the received pitch-angle values,
- after the first unit an electrically connected second unit (7) said second unit
(7) compares a reference-speed Sr received from the first unit (3) with an actual
speed Sa of the rotational speed of the motor (1), said resolver (5) measures and
calculates the actual speed Sa which is send to the second unit (7) and that the second
unit (7) regulates the rotational speed of the motor (1) according to the received
speed values
- after the second unit (7) an electrically connected third unit (10) comparing a
reference torque Tr of the motor (1) - said value is received from the second unit
(7) - with the actual torque Ta of the motor (1), said third unit (10) further regulates
the torque performance of the motor (1) according to the received torque-references;
said control system (2) further comprises a first overload unit (13) between the third
unit (12) and the motor (1)
characterized in
- that the control system (2) further comprises a second overload-unit (14) said second
overload unit (14) receives an error- speed-signal Se which is the difference between
Sr and Sa registered by the second unit (7)
- said second overload unit (14) compares Se with a maximal allowable speed value
Smax, and that the second overload unit (14) sends a signal to the motor (1) for the
regulating of the torque performance of the motor said signal is a function of the
value of Se.
2. Method according to claim1 characterized in that the signal is a maximum and preset torque value Tmax when Se is greater than Smax,
and the signal to the motor (1) is the torque value Ta received from the third unit
(10) when Se is less than or equal to Smax.
3. Method according to claim1 or 2
characterized in that the first unit (3) comprises a first summator (4) for comparison of the reference
pitch-angle Pr with the actual pitch-angle Pa of the turbine blade, and that the first
unit (3) further comprises a first control unit (6) for regulating the pitch-angle
of the turbine blade
- and that the second unit (7) comprises a second summator (8) for comparison of the
reference speed Sr with the actual speed Sa and comprises a second control unit (9)
for regulating the rotational speed of the motor (1)
and that the third unit (10) comprises a third summator (11) for comparison of the
reference torque Tr of the motor (1) with the actual torque Ta of the motor (1) and
that the third unit (10) further comprises a third control unit (12) for regulating
the torque of the motor (1).
4. Method according to any of the previous claims
characterized in that the second overload unit (14) comprises a comparator (15) and a switch (16) said
comparator (15) receives the speed signal Se from the second unit (7), said comparator
(15) compares Se with the maximum value for the speed Smax
- and that the comparator (15) sends a signal to the switch (16) that forwards the
signal in such a way, that a signal to the motor (1) for adjustment of its torque
is a maximum and predetermined torque value Tmax when Se is greater than Smax
- and that the signal to the motor (1) is the torque value Ta, which is a torque value
received from the third unit (10) when Se is less than or equal to Smax .
5. Method according to claim 4 characterized in that the switch (16) comprises a selector by which a comparison of the incoming speed
value of Se is evaluated in relation to Smax and in such a way that the value "fault"
is chosen when Se is less than Smax and the value "true" is chosen when Se is greater
than Smax.
6. Electrical pitch-control system (2) adapted to control a torque performance of an
electrical pitch motor (1) said pitch-control system (2) comprises
- a first unit (3) comprising a first summator (4) adapted to compare a received reference
pitch-angle Pr with an actual pitch-angle Pa of a turbine blade, said Pa-value is
provided by a resolver (5), and that the first unit (3) further comprises a first
control unit (6) adapted to regulate the pitch-angle of the turbine blade
- after the first unit (3) an electrically connected second unit (7) comprising a
second summator (8) adapted to compare a reference-speed Sr received from the first
unit (3) with an actual speed Sa of the rotational speed of the motor (1), measured
by the resolver (5)
- and a second control unit (9) adapted to regulate the rotational speed of the motor
(1) and after the second unit (7) an electrically connected third unit (10) comprising
a third summator (11) adapted to compare the reference torque Tr of the motor (1)
- said value is received from the second unit (7) - with the actual torque Ta of the
motor (1) and that the third unit (10) further comprises a third control unit (12)
adapted to regulate the torque of the motor (1)
- said control system (2) further comprises a first overload unit (13) between the
third unit (12) and the motor (1) characterized in
- that the control system (2) further comprises a second overload-unit (14) said second
overload unit (14) is adapted to receive an error-speed-signal Se which is the difference
between Sr and Sa registered by the second unit (7), said second overload unit (14)
is adapted to compare Se with a maximal allowable speed value Smax,
- and that the second overload unit (14) is adapted to send a signal to the motor (1) at which
signal the torque performance of the motor is regulated, said signal is a function
of the value of Se.
7. Use of the electrical pitch-control system according to claim 6 for carrying out the
method according to any of the claims 1-5
8. Use of the method according to claim 1-5 and according to the electrical pitch-control
system according to claim 6 and 7 for regulating a turbine blade of a with turbine
1. Verfahren zum Steuern oder Regeln eines Drehmoment-Verhaltens eines elektrischen Pitch-Verstellmotors
(1) in einem System, das ein elektrisches Pitch-Steuersystem (2) aufweist, wobei der
Pitch-Verstellmotor (1) ein Rotorblatt regelt oder steuert, wobei das Pitch-Steuersystem
(2) das Folgende aufweist:
- eine erste Einheit (3), die einen empfangenen Referenz-Pitchwinkel Pr mit einem
tatsächlichen Pitchwinkel Pa des Rotorblatts vergleicht, wobei der Pa-Wert von einem
Drehmelder (5) erfasst und von ihm empfangen wird und wobei die erste Einheit (3)
zudem den Pitchwinkel des Rotorblatts entsprechend den empfangenen Pitchwinkelwerten
einstellt,
- hinter der ersten Einheit eine elektrisch verbundene zweite Einheit (7), wobei die
zweite Einheit (7) eine Referenz-Geschwindigkeit Sr, die von der ersten Einheit (3)
empfangen wurde, mit einer tatsächlichen Geschwindigkeit Sa der Drehgeschwindigkeit
des Verstellmotors (1) vergleicht, wobei der Drehmelder (5) die tatsächliche Geschwindigkeit
Sa misst und berechnet, die an die zweite Einheit (7) gesendet wird, und wobei die
zweite Einheit (7) die Drehgeschwindigkeit des Verstellmotors (1) gemäß der erhaltenen
Geschwindigkeitswerte regelt,
- hinter der zweiten Einheit (7) eine elektrisch verbundene dritte Einheit (10), die
ein Referenz-Drehmoment Tr des Verstellmotors (1) - wobei dieser Wert von der zweiten
Einheit (7) erhalten wird - mit dem tatsächlichen Drehmoment Ta des Verstellmotors
(1) vergleicht, wobei die dritte Einheit (10) zudem das Drehmoment-Verhalten des Verstellmotors
(1) gemäß der empfangenen Referenz-Drehmomente regelt;
wobei das Pitch-Steuersystem (2) zudem eine erste Überlast-Einheit (13) zwischen der
dritten Einheit (12) und dem Verstellmotor (1) umfasst,
dadurch gekennzeichnet, dass
- das Pitch-Steuersystem (2) zudem eine zweite Überlast-Einheit (14) umfasst, wobei
die zweite Überlast-Einheit (14) ein Geschwindigkeitsfehler-Signal Se, das die Differenz
zwischen Sr and Sa ist, das von der zweiten Einheit (7) erfasst wird, empfängt,
- die zweite Überlast-Einheit (14) Se mit einem Höchstgeschwindigkeitswert Smax vergleicht
und dass die zweite Überlast-Einheit (14) ein Signal an den Verstellmotor (1) zum
Einstellen des Drehmoment-Verhaltens des Verstellmotors sendet, wobei das Signal eine
Funktion des Werts von Se ist.
2. Verfahren gemäß Anspruch 1, dadurch gekennzeichnet, dass das Signal ein maximaler und vorgegebener Drehmomentwert Tmax ist, wenn Se größer
als Smax ist, und dass das Signal an den Verstellmotor (1) der Drehmomentwert Ta ist,
der von der dritten Einheit (10) erhalten wird, wenn Se kleiner oder gleich Smax ist.
3. Verfahren gemäß Anspruch 1 oder 2,
dadurch gekennzeichnet, dass die erste Einheit (3) einen ersten Summenzähler (4) zum Vergleichen des Referenz-Pitchwinkel
Pr mit dem tatsächlichen Pitchwinkel Pa des Rotorblatts umfasst, und
dass die erste Einheit (3) zudem eine erste Steuer-Einheit (6) zum Einstellen des
Pitchwinkels des Rotorblatts aufweist
- und dass die zweite Einheit (7) einen zweiten Summenzähler (8) zum Vergleichen der
Referenz-Geschwindigkeit Sr mit der tatsächlichen Geschwindigkeit Sa umfasst und eine
zweite Steuer-Einheit (9) zum Regeln oder Steuern der Drehgeschwindigkeit des Verstellmotors
(1) umfasst
- und dass die dritte Einheit (10) einen dritten Summenzähler (11) zum Vergleichen
des Referenz-Drehmoments Tr des Verstellmotors (1) mit dem tatsächlich Drehmoment
Ta des Verstellmotors (1) umfasst und dass die dritte Einheit (10) zudem eine dritte
Steuer-Einheit (12) zum Regeln oder Steuern des Drehmoments des Verstellmotors (1)
umfasst.
4. Verfahren nach einem der vorstehenden Ansprüche,
dadurch gekennzeichnet, dass die zweite Überlast-Einheit (14) einen Komparator (15) und einen Schalter (16) umfasst,
wobei der Komparator (15) das Geschwindigkeitssignal Se von der zweiten Einheit (7)
empfängt, wobei der Komparator (15) Se mit dem Maximalwert für die Geschwindigkeit
Smax vergleicht
- und dass der Komparator (15) ein Signal an den Schalter (16) sendet, der das Signal
auf eine solche Weise weiterleitet, dass ein Signal an den Verstellmotor (1) zum Anpassen
des Drehmoments ein maximaler und vorgegebener Drehmomentwert Tmax ist, wenn Se größer
als Smax ist
- und dass das Signal an den Verstellmotor (1) der Drehmomentwert Ta ist, der ein
Drehmomentwert ist, der von der dritten Einheit (10) empfangen wurde, wenn Se kleiner
oder gleich Smax ist.
5. Verfahren gemäß Anspruch 4, dadurch gekennzeichnet, dass der Schalter (16) einen Selektor umfasst, mittels dem ein Vergleich des eingehenden
Geschwindigkeitswerts von Se in Relation zu Smax evaluiert wird und das auf solche
Weise, dass der Wert "Fehler" gewählt wird, wenn Se kleiner ist als Smax und dass
der Wert "wahr" gewählt wird, wenn Se größer ist als Smax.
6. Elektrisches Pitch-Steuersystem (2), das ausgebildet ist zum Steuern oder Regeln eines
Drehmoment-Verhaltens eines elektrischen Pitch-Verstellmotors (1), wobei dieses Pitch-Steuersystem
(2) das Folgende umfasst:
- eine erste Einheit (3) mit einem ersten Summenzähler (4), der ausgebildet ist zum
Vergleichen eines empfangenen Referenz-Pitchwinkel Pr mit einem tatsächlichen Pitchwinkel
Pa eines Rotorblatts, wobei der Pa-Wert von einem Drehmelder (5) bereitgestellt wird,
wobei die erste Einheit (3) zudem eine erste Steuer-Einheit (6) umfasst, die ausgebildet
ist zum Einstellen des Pitchwinkels des Rotorblatts,
- hinter der ersten Einheit (3) eine elektrisch verbundene zweite Einheit (7), die
einen zweiten Summenzähler (8) umfasst, der ausgebildet ist zum Vergleichen einer
Referenz-Geschwindigkeit Sr, die von der ersten Einheit (3) empfangen wird, mit einer
tatsächlichen Geschwindigkeit Sa der Drehgeschwindigkeit des Verstellmotors (1), die
vom Drehmelder (5) gemessen wird,
- und eine zweite Steuer-Einheit (9), die eingerichtet ist zum Regeln der Drehgeschwindigkeit
des Verstellmotors (1), und nach der zweiten Einheit (7) eine elektrisch angeschlossene
dritte Einheit (10), die einen dritten Summenzähler (11) aufweist, der ausgebildet
ist zum Vergleichen des Referenz-Drehmoments Tr des Verstellmotors (1) - wobei dieser
Wert von der zweiten Einheit (7) erhalten wird - mit dem tatsächlich Drehmoment Ta
des Verstellmotor (1), wobei die dritte Einheit (10) zudem eine dritte Steuer-Einheit
(12) umfasst, die eingerichtet ist zum Einstellen des Drehmoments des Verstellmotors
(1),
- wobei das Pitch-Steuersystem (2) zudem eine erste Überlast-Einheit (13) zwischen
der dritten Einheit (12) und dem Verstellmotor (1) umfasst, dadurch gekennzeichnet,
- dass das Pitch-Steuersystem (2) zudem eine zweite Überlast-Einheit (14) umfasst, wobei
die zweite Überlast-Einheit (14) eingerichtet ist zum Empfangen eines Geschwindigkeitsfehler-Signals
Se, das die Differenz zwischen Sr and Sa, die von der zweiten Einheit (7) erfasst
wurde, ist, wobei die zweite Überlast-Einheit (14) eingerichtet ist zum Vergleichen
von Se mit einem Höchstgeschwindigkeitswert Smax,
- und dass die zweite Überlast- Einheit (14) eingerichtet ist zum Senden eines Signals an den
Verstellmotor (1), auf welches Signal hin das Drehmoment-Verhalten des Verstellmotors
gesteuert wird, wobei das Signal eine Funktion des Werts von Se ist.
7. Verwendung des elektrischen Pitch-Steuersystems gemäß Anspruch 6 zum Ausführen des
Verfahrens nach einem der Ansprüche 1 bis 5.
8. Verwendung des Verfahrens gemäß einem der Ansprüche 1 bis 5 und gemäß dem elektrischen
Pitch-Steuersystem gemäß Anspruch 6 und 7 zum Regeln eines Rotorblatts einer Windkraftanlage.
1. Procédé de commande d'une performance de couple d'un moteur de pas électrique (1)
dans un système comprenant un système de commande de pas électrique (2), ledit moteur
de pas (1) commandant une aube de turbine, ledit système de commande de pas (2) comprenant
- une première unité (3) comparant un angle de pas de référence reçu Pr avec un angle
de pas réel Pa de l'aube de turbine, ladite valeur de Pa est enregistrée par un résolveur
(5) et reçue de celui-ci, et la première unité (3) régule en outre l'angle de pas
de l'aube de turbine en fonction des valeurs d'angle de pas reçues,
- après la première unité, une deuxième unité connectée électriquement (7), ladite
deuxième unité (7) compare une vitesse de référence Sr reçue de la première unité
(3) à une vitesse réelle Sa de la vitesse de rotation du moteur (1), ledit résolveur
(5) mesure et calcule la vitesse réelle Sa qui est envoyée à la deuxième unité (7)
et la deuxième unité (7) régule la vitesse de rotation du moteur (1) en fonction des
valeurs de vitesse reçues
- après la deuxième unité (7), une troisième unité (10) connectée électriquement comparant
un couple de référence Tr du moteur (1) - ladite valeur est reçue de la deuxième unité
(7) - avec le couple réel Ta du moteur (1), ladite troisième unité (10) régule en
outre la performance de couple du moteur (1) en fonction des références de couple
reçues ;
ledit système de commande (2) comprend en outre une première unité de surcharge (13)
entre la troisième unité (12) et le moteur (1),
caractérisé en ce que
- le système de commande (2) comprend en outre une deuxième unité de surcharge (14),
ladite deuxième unité de surcharge (14) recevant un signal de vitesse d'erreur Se
qui est la différence entre Sr et Sa enregistrées par la deuxième unité (7)
- ladite deuxième unité de surcharge (14) compare Se avec une valeur de vitesse maximale
admissible Smax, et en ce que la deuxième unité de surcharge (14) envoie un signal au moteur (1) pour la régulation
de la performance de couple du moteur, ledit signal étant fonction de la valeur de
Se.
2. Procédé selon la revendication 1, caractérisé en ce que le signal est une valeur de couple maximale et prédéfinie Tmax lorsque Se est supérieure
à Smax, et le signal au moteur (1) est la valeur de couple Ta reçue de la troisième
unité (10) lorsque Se est inférieure ou égale à Smax.
3. Procédé selon la revendication 1 ou 2,
caractérisé en ce que la première unité (3) comprend un premier sommateur (4) pour une comparaison de l'angle
de pas de référence Pr avec l'angle de pas réel Pa de l'aube de turbine, et
en ce que la première unité (3) comprend en outre une première unité de commande (6) pour réguler
l'angle de pas de l'aube de turbine
- et que la deuxième unité (7) comprend un deuxième sommateur (8) pour comparer la
vitesse de référence Sr à la vitesse réelle Sa et comprend une deuxième unité de commande
(9) pour réguler la vitesse de rotation du moteur (1)
et
en ce que la troisième unité (10) comprend un troisième sommateur (11) pour comparer le couple
de référence Tr du moteur (1) au couple réel Ta du moteur (1), et
en ce que la troisième unité (10) comprend en outre une troisième unité de commande (12) pour
réguler le couple du moteur (1).
4. Procédé selon l'une quelconque des revendications précédentes,
caractérisé en ce que la deuxième unité de surcharge (14) comprend un comparateur (15) et un commutateur
(16), ledit comparateur (15) reçoit le signal de vitesse Se de la deuxième unité (7),
ledit comparateur (15) compare Se à la valeur maximale de la vitesse Smax
- et en ce que le comparateur (15) envoie un signal au commutateur (16) qui transmet le signal de
telle sorte qu'un signal destiné au moteur (1) pour un ajustement de son couple soit
une valeur de couple maximale et prédéterminée Tmax lorsque Se est supérieure à Smax
- et en ce que le signal au moteur (1) est la valeur de couple Ta, qui est une valeur de couple
reçue de la troisième unité (10) lorsque Se est inférieure ou égale à Smax.
5. Procédé selon la revendication 4, caractérisé en ce que le commutateur (16) comprend un sélecteur au moyen duquel une comparaison de la valeur
de vitesse entrante de Se est évaluée par rapport à Smax et de telle sorte que la
valeur « fausse » est choisie lorsque Se est inférieure à Smax et que la valeur «
vraie » est choisie lorsque Se est supérieure à Smax.
6. Système de commande de pas électrique (2) adapté pour commander une performance de
couple d'un moteur de pas électrique (1), ledit système de commande de pas (2) comprend
- une première unité (3) comprenant un premier sommateur (4) adapté pour comparer
un angle de pas de référence reçu Pr avec un angle de pas réel Pa d'une aube de turbine,
ladite valeur de Pa étant fournie par un résolveur (5), et la première unité (3) comprend
en outre une première unité de commande (6) adaptée pour réguler l'angle de pas de
l'aube de turbine
- après la première unité (3), une deuxième unité (7) connectée électriquement comprenant
un deuxième sommateur (8) adapté pour comparer une vitesse de référence Sr reçue de
la première unité (3) avec une vitesse réelle Sa de la vitesse de rotation du moteur
(1), mesurée par le résolveur (5)
- et une deuxième unité de commande (9) adaptée pour réguler la vitesse de rotation
du moteur (1) et, après la deuxième unité (7), une troisième unité (10) connectée
électriquement comprenant un troisième sommateur (11) adapté pour comparer le couple
de référence Tr du moteur (1) - ladite valeur est reçue de la deuxième unité (7) -
avec le couple réel Ta du moteur (1), et la troisième unité (10) comprend en outre
une troisième unité de commande (12) adaptée pour réguler le couple du moteur (1)
- ledit système de commande (2) comprend en outre une première unité de surcharge
(13) entre la troisième unité (12) et le moteur (1), caractérisé en ce que
- le système de commande (2) comprend en outre une deuxième unité de surcharge (14),
ladite deuxième unité de surcharge (14) est adaptée pour recevoir un signal de vitesse
d'erreur Se qui est la différence entre Sr et Sa enregistrée par la deuxième unité
(7), ladite deuxième unité de surcharge (14) est adaptée pour comparer Se avec une
valeur de vitesse maximale admissible Smax,
- et en ce que la deuxième unité de surcharge (14) est adaptée pour envoyer un signal au moteur
(1), signal au niveau duquel la performance de couple du moteur est régulée, ledit
signal étant fonction de la valeur de Se.
7. Utilisation du système de commande de pas électrique selon la revendication 6 pour
mettre en œuvre le procédé selon l'une quelconque des revendications 1 à 5.
8. Utilisation du procédé selon les revendications 1 à 5 et selon le système de commande
de pas électrique selon les revendications 6 et 7 pour réguler une aube de turbine
d'une turbine.